This invention relates to medical apparatus, particularly apparatus for assisting radioscopic examinations where precision in the focus and targeting of radiation is desired. The apparatus of this invention comprises a radiolucent table top having support means for limited bidirectional movement of the top with respect to the radioscopic source.
In certain radiology procedures, for example in discolosis treatment by lamenectomy and particularly chemonucleolysis, it is desirable to position the radioscopic source directly over the affected spinal disc. Because of the weight and inherent inertia of the radioscopic source, usually a C-arm fluoroscope, the final targeting of the radiation beam is difficult to accurately control. Movement of a radiology table may also be difficult to control.
Targeting of the radiation beam is important in discolysis procedures because the affected disc is examined on edge, with the patent lying on the table in a lateral decubital. In discolysis, radioscopic examination may occur in diagnosis prepatory to treatment, and during injection of a lysing agent for disolving the nucleus pulposus in a herniated disc in chemonucleolysis procedures, again for accurate needle placement.
In chemonucleolysis procedures, particularly utilizing a needle guide apparatus as described in the patent entitled Needle Guide Apparatus for Discolysis Procedures, issued on Jan. 27, 1987, U.S. Pat. No. 4,638,799, apparatus adjustment and final location of the injection needle is monitored radioscopically with reference to radio-opaque indicator means. In order to accurately monitor the relative position of the apparatus with respect to the patient, the radiation beam should be centrally aligned with the indicator means. The fine adjustments necessary cannot be adequately obtained by movement of a conventional radiology table or radioscopic source.
Other radiological procedures for examination or treatment may require similar demanding adjustments not achievable by conventional apparatus.
In order to solve these problems, the radiolucent table extension of this invention was devised.